1. Field of the Invention
The invention concerns a method for the mechanical production of pieces of the same length of fish conveyed transverse to their longitudinal axis as well as an apparatus for carrying out such a method, this apparatus comprising a trough conveyor which conveys the fish transverse to their longitudinal axis and at least one cutting means which overlaps at least the cross-sectional area of fish placed in the conveying troughs, the apparatus further comprising a displacing device for displacing fish tail first and an abutting device for limiting the displacement of the fish by catching the same by their tail roots.
2. Description of Prior Art
Such fish pieces which are preferably produced from sardines, herrings, anchovies etc. are needed essentially as a filler for tins. They are offered to the consumer prepared in different ways. The tail pieces are usually preferred since especially in single reciprocal layers of such pieces a more profitable rate of feeding and a product which is more pleasing to the eye are achieved. Problems arise in trying to fulfil the quality demands in this respect as well as with regard to the weight tolerance, which problems are mainly due to the fact that the fish to be processed are of different lengths and maturity. The usual practice of putting a uniform number of pieces--for example four--into tins, requires a pre-sorting into several classes of small size and thickness tolerance due to differences in size and thickness. The device for cutting the pieces thus has to be adjustable to each necessary piece length. This is extremely difficult to achieve with the machines known so far so that these machines and the methods practised therewith are not satisfactory.
A piece cutting device is known (e.g. U.S. Pat. No. 2,431,465) in which the fish are conveyed in the troughs of a trough conveyor transverse to their longitudinal axis. The upwardly extending walls of the troughs are provided with slots extending to under their bottom surface, at least one circular knife arranged above the trough conveyor entering into them. In order to sufficiently support the fish the slots lie at such a distance from each other that leftovers of the peripheries remain between the slots. Apart from the fact that only pieces of the same length--regarding the plane of decapitating--can be manufactured, the tail piece being the remnant, the shifting of the knife in order to achieve a different length for the pieces is very complicated and only possible in relatively rough gradation.
There is further known (DE-PS No. 717 592) a device for the production of so-called "fork-size bites" whereby the fish not yet decapitated are inserted, after their tail fin has been removed, with their head facing the centre into a circular conveyor with partitions consisting of ridges running above a circular table. The circular table has openings. After being aligned with their snouts in the same position by means of a guide the fish fall through the openings into a set of pairs of disc knives which shear with each other and carry out the transverse severing. The disadvantages laid down in connection with the first-mentioned cutting device are also found here. However, a more delicate adjustment of the desired piece lengths is possible.
Furthermore, a piece cutting or slicing device is known (DE-PS No. 26 44 024) in which the head end of the fish forms the remnant piece. The fish rumps lying in the receiving troughs are, for this purpose, pushed in the direction of their tail end under a measuring bar which forms an abutment supporting itself on the flank of the fish. Thus positioned, the fish rumps are led to a fixed circular knife which cuts off tail pieces of almost the same weight but differing lengths. Such fish pieces facilitate the compilation of a certain filler weight but make a reasonable positioning in the tins impossible.
3. Object of the Invention
It is therefore an essential object of the present invention to show a way of manufacturing fish tail pieces of the same length which makes a continuous adjustment of the lengths of these pieces in a simple manner possible.